Looms



I March 4, 1969 D. w. SHIMWELL LOOMS I of 4 Sheet Filed March 23, 1967 a{nvenfor March 4, 1969 D. w. SHIMWELL LOOMS Sheet Filed March 25, 1967March 4, 1969 D. w. SHIMWELL 3,

LOOMS Filed March 23, 1967 Sheet 3 of 4 I nvenlor By Q 7 b A lornefiMarch 4, 1969 w. SHIMWELL 3,430,664

LOOMS Filed March 25, 1967 Sheet 4 of 4 United States Patent 3,430,664LOOMS Derrick Walter Shimwell, Jurby, Isle-of-Man, assignor to WeavingResearch & Textile Commission Agents Limited, a British company FiledMar. 23, 1967, Ser. No. 625,480 Claims priority, application GreatBritain, Mar. 30, 1966, 14,100/ 66 US. Cl. 13912 21 Claims Int. Cl. D03d47/34 ABSTRACT OF THE DISCLOSURE In a needle loom in which weft yarn issupplied from stationary packages to oscillating weft inserting means tobe inserted into warp sheds, a reservoir in which the weft can betemporarily stored during its passage from said supply to said insertingmeans, wherein a reservoir for weft yarn is provided for at least one ofthe spears or the like, and a gas jet is positioned to blow weft yarninto. the reservoir from a supply package, the arrangement being suchthat weft yarn can be drawn from the reservoir by the spears as and whenneeded during running of the loom.

Description of invention This invention relates to looms in which theweft is not carried in the form of pirns or cops by shuttle but issupplied from stationary packages and is inserted through the warp shedby means of, for example, spears or rapiers.

A loom of this type can insert weft yarn at a higher speed than theconventional fiat shuttle loom but the weft yarn is only in intermittentdemand. For example, if the weft is inserted by spears from either sideof the cloth the intermittent demand causes plucking of yarn from thesupply packages and the yarn is only drawn intermittently from thesupply packages or cones. Furthermore, at some points in the layingcycle, the point at which laying of yarn begins is remote from thesupply package and the yarn is laid at a point where the spear istravelling fast causing high yarn tension which acts to augment theeffect of plucking of the yarn from the supply package. A combination ofthese two factors has been found to be a cause of weft breakage.

A loom of the spear type in accordance with this invention has a weftreservoir for one, or normally each, spear into which weft yarn is blownfrom a supply package by a jet of, for example, air and from which theyarn may be drawn by the spears as and when needed.

The pressure of the air issuing from the jet may be adjusted so that theyarn is drawn from the supply package into the reservoir at asubstantially constant rate without plucking so that the tension in theweft yarn will thus be substantially reduced, allowing weaving at higherspeeds and with less yarn breaks than has been the case hitherto. Theyarn is then drawn from the reservoir intermittently by the spears andfor each laying cycle the feed of weft yarn to the reservoir from thesupply packages will approximately equal the length of yarn drawn fromthe reservoir intermittently by the spears. For example, if single pickcloth is being woven with the spears laying yarn only on every alternatemovement across the cloth, the rate of supply of weft to the reservoirwhich occurs during both movements, has to approximate to half that atwhich the spears take-up yarn from the reservoir during their layingmovement. Of course the loom can also weave double pick cloth when thedemand for weft will be doubled and an increase in air pressurerequired.

The reservoir is conveniently in the form of a tube, the diameter ofwhich may depend on the range of yarns being woven, and the pressure ofair blown into it is also ice variable to suit the weight of yarn. Inone typical example for jute hessian yarn the reservoir is 10 to 12inches long, diameter, and the air pressure is approximately 7 to 8 lbs.per square inch.

The air blowing into the reservoir is conveniently released from a holeor holes through the wall of the reservoir or at the outlet end thereofso that the yarn is not blown out from the reservoir to the spears whenthis is not required.

A single outlet hole is preferred and a cover may be provided to allowair only to pass outwardly from the tube, the cover which is akin to aflap valve closing to prevent air entering when a threading-up operationis taking place.

In practice it is very difficult to arrange for the air et to supply theexact amount of yarn needed to the reservoir as, for example, the widthof the cloth can vary or the corrugations of the weft may vary. Thisdifliculty may be overcome by arranging for the air jet to supplyslightly more weft yarn to the reservoir than the expected demand andthen providing a passage or passages, at the inlet end of the reservoirto allow the incoming air jet to be spilled-back when the length of yarnin the reservoir is sufficient to create a back-pressure overcoming thepressure of the incoming air. This has the effect of cutting down thequantity of yarn being fed to the reservoir if there is an excessiveamount therein. As the excess is used up the normal feed willautomatically be resumed.

An air jet nozzle may also be present at the outlet end of the reservoiror between the reservoir and the spear to blow the weft yarn to thespear head. This jet is preferably only operative as and when the spearis laying yarn and will not operate for the remaining portion of thespear cycle. It will normally only be used with heavy yarns such asjute, sacking weft and hard fibre yarns. An additional nozzle may bepositioned at the outlet of the reservoir to facilitate threading-up ofthe spear.

If the reservoir is employed with a loom in which the spears arereciprocated in a straight line, means such as the linkage described inthe specification of our U.S. Patent No. 2,860,667 may be provided totake-up the slackness of the weft yarn which occurs during part of eachcycle of spear movement. In such a case the reservoir may either belocated between the supply package and the first pivotal link or it maybe carried by, or from, one of the links.

If the reservoir is employed with a loom such as that forming thesubject of our co-pending US. application Ser. No. 625,479 then nolinkage is needed as the weft yarn is being woven in an arc and may befed from a point (for example, the outlet of the reservoir) atapproximately the centre of the arc.

The invention will now be further described by way of eiilample withreference to the accompanying drawings in w ich:

FIGURE 1 is a sketch illustrating the use of an air fed weft reservoirwith a spear loom of the type forming the subject;

FIGURE 2 is a detail of the air escape hole at the reservoir outlet;

FIGURES 3-6 are diagrams illustrating the use of a weft reservoir withoth r typ s of spear looms;

FIGURE 7 is a sketch of an alternative form of weft reservoir; and

FIGURE 8 is a section outline VIIIVHI of FIG- URE 7.

Referring to FIGURE 1 the loom comprises two curved weft insertingneedles, hereinafter called spears, 2, 4 each carried at the end of anarm 6 or 8 respectively. The arms are joined and are mounted for arcuatemovement about a common shaft 10. On oscillation of the shaft the spearsare caused to move in an arc in the same path and to lay weft inseparate sheds (for further details of the operation of the loomreference should be made to the specification of our co-pending U.S.application Ser. No. 625,479). It will be appreciated that FIGURE 1omits all details of the loom with the exception of those necessary tothe proper understanding of this invention. Also for convenience areservoir is only shown for the left hand spear 2, a similar reservoiris present in practice for the weft fed to the right hand spear 4.

The weft supply for the left hand spear 2 comprises two tag-ended cones12, mounted within a shield 14. A weft reservoir 18 in the form of apolythene tube of about /4" to 1" diameter, is attached to the shield 14and yarn is drawn from one of the cones through the inlet of thereservoir.

The tube 18 is pivotally mounted at its inlet end by means not shown inthe sketch and is pivotally connected at its outlet end by an outletelbow 22 to a pipe 24 which extends along the length of the arm 6 andconnects with a further pipe or passage 26 extending along the spear andterminating at the spear head 28.

A source of compressed air is connected through an adjustable reducingvalve 30 through a pipe 32 to a nozzle 34 which is positioned to be openthrough the wall of the inlet tube 20 to blow a jet of air through theinlet 20 into the reservoir. The jet is continuous and acts to draw theweft yarn into the reservoir where it accumulates in a number of coilsindicated at 36 (FIG. 7).

The weft is laid by the spears intermittently and so the demand for weftyarn to be drawn from the reservoir is intermittent. However due to theaccumulation of yarn in the reservoir the intermittent demand is nottransmitted to the cones and yarn is drawn therefrom without significantor abrupt changes in tension. The pressure of the air jet through thenozzle 34 is adjusted so that the consumption of yarn is approximatelyequal the supply of yarn to the reservoir.

If too much yam accumulates in the reservoir, a back pressure is createdthus reducing the efliciency of the air jet so that a reduced amount ofyarn is introduced into the reservoir as and until the excess yarn hasbeen used.

During normal running the air from the nozzle 36 escapes through anescape hole 38 in the outlet 22 of the reservoir (see FIGURE 2) and sodoes not act to feed yarn to the spear.

The hole 38 is provided with a hinged cover 40 (FIG. 2) which allows airto escape from the outlet 22 but which prevents air from being suckedinto the outlet.

It has been found that with certain heavy yarn e.g. jute sacking weftand hard fibre, it is convenient to provide a second air jet to assistthe passage of the yarn down the spear. This jet is fed from the sourceof compressed air through a reducing valve 42, pipe 44 and valves 46operated by earns 48, to nozzles 50 open to the inner end of the spearpassages 26.

As yarn is only laid by the spears at intermittent intervals, the jet isonly operated at those intervals so as to prevent excess yarn billowingfrom the spear heads. This is achieved by the choice of a suitable shapefor the earns 48 which are driven from a shaft 52 rotating in time withthe operation of the other parts of the loom. As an example the pressureof the air at the nozzle 50 may be 20-30 lbs. per square inch the exactfigure will in each case be determined by experiment.

As the point of connection of the reservoir to the arm 6 is adjacent thepillar 10 about which the arms 6, 8 oscillate (or it may be preferableto mount the elbow 22 directly above the pillar) and as the spears aremoving in an arcuate path with the laying point at a constant distancefrom the pillar, it will be appreciated that the weft path is alwayssubstantially constant and hence the need for linkage to take-up surplusyarn during part of the cycle of spear movement is obviated.

When it is desired to thread-up the spears a valve (not shown) is openedto allow a strong blast of air to blow through a nozzle 54 at the end ofan air pipe 55, the nozzle connecting with the outlet elbow 22 after theescape hole 38 causing yarn to be fed from the reservoir and passages 24and 26 to the spear head, the grippers (not shown) at the spear headsbeing opened to allow the yarn to emerge. A good suction for thereservoir is achieved as the cover 40 for the escape hole closes toprevent air being drawn into the outlet by the jet.

In the arrangement illustrated in FIGURE 3, a reservoir tube 60 islocated at each side of a spear loom (only one side being shown) andyarn is fed into the reservoir from a supply cone 62 by an air jet 64.The yarn then passes along pipes connected as pivotal links 66, 68 forthe purpose of the taking up surplus of yarn as described in thespecification of our U.S. Patent No. 2,860,667. The yarn is then fed tothe inner end of a spear 70 reciprocating in a straight line path. Theyarn may be assisted in its passage through the links by a second airjet 72.

Air can escape from the reservoir either at the inlet if this is foundto be necessary or through holes 74 in the side of the reservoir tubeadjacent the outlet end.

For details of the construction and operation of a loom having spearsmoving in a straight line path reference may be made to thespecification of our U.S. Patent No. 2,816,576.

The embodiment shown in FIGURE 4 differs from that of FIGURE 3 only inthat the reservoir tube is bent through 180 allowing for a more compactarrangement.

If desired the reservoir tube 60 can be carried by or can replace thelink 66 and such an arrangement is shown in FIGURE 5.

As shown in FIGURE 6 the arms 66, 68 are replaced by a single arm 75 tocontrol the weft and remove the yarn from the reservoir in a moreuniform manner. The reservoir 60 is located between the eye 76 Where theweft yarn engages the spear 70, and the cone 62.

It will be appreciated that the tension of yarn being drawn from a conetends to increase as the diameter of the cone diminishes. It isenvisaged that if necessary the pressure of the jet at the inlet end ofthe reservoir could be varied as the cone size decreases.

As an alternative the weft yarn reservoir shown in any one of FIGURES1-6 could be of the form shown in FIGURES 7 and 8. This with reservoir80 is rectangular in section as can be seen in FIGURE 8 and has adimension at the inlet 20 not significantly greater than that of thetube 20 so as to limit the turbulence where the air jet enters thereservoir. The reservoir then increases in one dimension as seen in thedrawing so as to allow the yarn coils to move down the reservoir withoutundue friction. The reservoir terminates at a tapering section connectedto the outlet elbow 22. An air escape hole 82 is formed adjacent theoutlet for the reservoir and again a flap valve 84 is provided toprevent air being sucked into the air lines.

The reservoir would normally be of rigid material with at least one wall86 transparent.

It has been found that the use of the reservoir shown in FIGURES 7 and 8considerably reduces the pressure of air needed properly to feed weft tothe reservoir and hence results in a more eflicient performance.

I claim:

1. In a needle loom in which weft yarn is supplied from stationarypackages to oscillating weft inserting means to be inserted into warpsheds, storage means in which the weft can be temporarily stored duringits passage from said supply to said inserting means, wherein saidstorage means for weft yarn is in communication with said weft insertingmeans, a gas jet positioned to blow weft yarn into the storage meansfrom said supply package, the arrangement being such that weft yarn canbe drawn from the storage means by the weft inserting means as neededduring weaving.

2. A loom as claimed in claim 1 in which said weft inserting meanscomprises a spear provided at each side of the loom and said storagemeans comprises a plurality of reservoirs whereby a reservoir isprovided for each spear.

3. A loom as claimed in claim 1 in which each jet is connected to asource of compressed air.

4. A loom as claimed in claim 3 in which means are provided to adjustthe pressure of the gas.

5. A loom as claimed in claim 2 in which each reservoir is in the formof a tube.

6. A loom as claimed in claim 2 in which each reservoir is rectangularin section and has an air inlet pipe.

7. A loom as claimed in claim 6 in which each reservoir has a sectionwhich tapers outwardly in one direction from a dimension at the inletwhich is substantially equal to the dimension of the air inlet pipe.

8. A loom as claimed in claim 2 in which a yarn passage is providedbetween each reservoir and the head of its respective spear.

9. A loom as claimed in claim 8 wherein escape valve means are providedat the outlet end of each reservoir.

10. A loom as claimed in claim 9 in which each reservoir has only asingle escape valve which is normally closed by a cover arranged toallow air only to pass outwardly from the reservoir and to prevent airfrom being sucked into the reservoir.

11. A loom as claimed in claim 8 in which a passage is provided at theinlet end of each reservoir to allow the incoming gas jet to escape whenthe reservoir is sufiiciently supplied with yarn to create a backpressure.

12. A loom as claimed in claim 11 in which a second jet nozzle ispresent between the outlet end of each reservoir and the spear head toassist in blowing yarn to the spear head.

13. A loom as claimed in claim 12 in which means are provided toenergise the second jet only during those portions of the weaving cyclewhen the respective spear is laying yarn.

14. A loom as claimed in claim 2 in which a further nozzle is positionedadjacent the outlet of each reservoir to provide a jet which in usehelps to suck yarn from the reservoir and to blow it to the spear headto facilitate threading-up of the respective spear.

15. A loom as claimed in claim 2 in which the spears are reciprocated inan arc with the reservoir extending radially from the center of the areso that the weft yarn path length remains substantially constantthroughout weaving.

16. A loom as claimed in claim 15 wherein said reservoirs are mounted toa common pillar which is located at the center of the arc and on whichtwo arms, each of which carries one of the spears, are pivotallymounted.

17. A loom as claimed in claim 2 in which the spears are driven in astraight line, means are provided to take up the slack in the weft yarnwhich occurs during each weft inserting cycle.

18. A loom as claimed in claim 17 in which the said means comprises foreach spear two pivotal links, the reservoir being located between thesupply package and the first pivotal link.

19. A loom as claimed in claim 18 wherein at least part of the reservoiris flexible and is mounted in a curved position.

20. A loom as claimed in claim 17 in which the said means comprises foreach spear, two pivotal links, the reservoir being carried by one of thelinks.

21. A loom as claimed in claim 17 in which the said means comprises foreach spear a single arm which engages the yarn between the reservoir andthe spear.

References Cited UNITED STATES PATENTS 1,361,530 12/1920 Morris 139-1232,860,667 11/1958 Shimwell 139-123 3,137,322 6/1964 Strake 1391273,194,276 7/1965 Krukonis et al. 139-122 FOREIGN PATENTS 174,387 2/1961Sweden.

HENRY S. JAUDON, Primary Examiner.

US. Cl. X.R.

